Liquid level indicating means



Oct. 21, 1947. SCULLY ET L 2,429,280

LIQUID LEVEL INDICATING MEANS Original Filed Sept. 19, 1941 INVENTORS Patented Oct. 21, 1947 LIQUID LEVEL INDICATIN G DIE'AN S Frank P. Scully, Cambridge, and Alcide E.

Mathey, Allston, Mass.,

assignors to Scully Signal Co., East Cambridge, Mass., a corporation of Massachusetts 7 Original application September 19, 1941, Serial No. 411,600. Divided and this application June 22, 1944, Serial No. 541,518

3 Claims.

This invention relates to the provision of means for indicating the level of the liquid in tanks, and is a division of the application of Frank P. Scully and Alcide E. Mathey for Liquid level indicating means, filed September 19, 1941, Serial No. 411,600.

As is well known, in filling tanks it is ordinarily desirable to fill the tank as a full as possible without overflowing. It is one of the objects of this invention to provide means which will indicate to the operator when the filling has proceeded to a point very close to the top of the tank, so that the supply may then be terminated before overflowing takes place.

This invention is particularly adapted for use with small tanks of the size used, for example, on automobiles, where absence of indicating means often results in overflowing.

The construction that we use to advise when filling has been completed includes a whistle capable of givin a sufficiently loud sound to be readily heard by the operator. The whistle is positioned in the path of venting gases and so constructed that adequate venting capacity will always be available regardless of the rate of fill and the degree to which the tank has been filled.

Other objects and accomplishments of our invention will became more apparent as the description proceeds with the aid of the accompanying drawings, in which:

Fig. 1 shows a tank having filling and venting connections:

Fig. 2 shows one form of audible signaling device that may be used, in which the whistlin is affected by a change in the nature of the air stream passing through the whistle.

Fig. 3 is a modification in which the auxiliary venting means is remote from the signaling device.

Fig. 4 shows still another modification with remote auxiliary venting.

Fig. 5 is another form in which the whistle is free to float to provide auxiliary venting,

Fig. 6 is another form similar to that shown in Fig. 5, plus the addition of an intrusion tube for cutting oil the signal.

In Fig. l is shown diagrammatically a typical fuel tank such as may be found on an automobile. This consists of a tank 2, fill pipe 4 and vent pipe 6. The fill pipe 4 is shown as entering the tank at the bottom, giving what is known as a deep fill, but for the purposes of this invention the filling may take place at any desired point. However, whatever filling means is provided, it is contemplated that the gases vented from the tank will not be vented back through the fill pipe,-

. are the provision of a tight connection at the filler neck between the fluid supply line and the fill pipe, provision of a change in direction of the filler. pipe so that the entering liquid will completely fill the pipe at that point, thereby preventing the escape of gases, and the provision of a deep fill, which is indicated in Fig. 1.

The vent pipe 6 may likewise be positioned at any convenient point on the upper portion of the tank and provides means through which gas displaced by the entering liquid may escape.

For convenience in applying our invention, a housing 8 is provided under which is positioned the audible signaling device that will hereinafter be described.

One form of our invention is shown in Fig. 2, in which there is a whistle ID of the hollow button type, usually cylindrical in plan, which is secured in place in a corresponding opening in the top of tank 2. Whistle ID has centrally located holes [2 and M which cause a distinct whistling sound when gas is passed therethrough. Whistles of this construction require very little pressure for satisfactory operation, and the pressure developed in the ordinary filling of a tank is adequate for good audibility.

It is apparent that with the whistle structure of Fig. 2, whistling will proceed as the tank is being filled. In order to indicate to the operator when the filling has been completed, we provide a float l6 which may be of cork or other buoyant material or in the form of a hollow member, all of which are adapted to rise under the influence of the mounting liquid level.

The float l6 may be guided in any convenient manner. In the form shown. we have provided a frame l8 which may depend from whistle III, as shown, or from the tank, if desired. Frame l8 carries the vertical member 20 which extends through a vertical centrally located hole in float IS. The guide means, however, is only illustrative, and we contemplate that in this form of our invention and in all of the other forms shown the guide means for the various floats may be of any convenient structure.

As the filling proceeds, it is apparent that float l6 will ascend to the dotted line position indicated, and at that point the upper end of the float will be close to the hole 44 of whistle l0, but will be prevented from reaching and closing the whistle apertures because of stop 22 on the upper should be understood. however,

end of guide 20. Float l8, however, approaches so closely to whistle i that the direction of gas entering and passing through the whistle is so altered and distorted that the resonance is destroyed, with the result that whistling ceases. It that float I6 is not permitted to interfere with the venting capacity or the whistle, even though the air stream is altered, for the reason that the effective area between float l8 and the whistle is not reduced below the area of the holes [2 and I4.

Thus, when float It has risen to the upper position shown and the whistling has ceased, the operator will be advised that the tank is full.

The constructions shown in Figs. 3, 4, 5 and 6 differ from that shown in Fig. 2 in that auxiliary venting means apart from the whistle itself is provided. It will be noted in Fig. 2 that the escaping gas must pass through apertures in the whistle itself, whereas in Figs. 3, 4, 5 and 6 escaping gas may pass not only through the whistle, but also through other ports, if the pressure in the tank becomes sufllcient to warrant auxiliary venting.

In Fig. 3 a construction is shown in which the auxiliary venting means-is apart from the whistle itself. In this form whistle I0 is secured in a suitable aperture in the top of tank 2 the same as in the construction of Fig. 2. The auxiliary venting means is provided by a series of holes 36 extending circumferentially through the tanktop and about whistle i0. Holes 38 are normally closed by an annular valve member 38. If the pressure in the tank becomes excessive so that orifices l2 and M are inadequate, the gas pressure through holes 38 will cause valve 38 to lift, thereby providing additional venting capacity. Excessive upward movement of valve 38 is prevented by housing .8.

The whistling in the construction of Fig. 3 is controlled in the following manner: Float i8 is guided by member 20 so that as the liquid level rises, the orifices through the whistle ID will finally be closed, causing cessation of the whistling sound, indicating to the operator that the tank is full. Further escape of gas thereafter is provided for by means of holes 38 and pressure-operated valve 38.

, The construction of Fig. 4 is a modification of that shown in Fig. 3. Instead of providing a series of holes covered by an annular valve, we have here provided a single larger hole 40 normally closed by a ball valve 42. When the pressure caused by escaping gas becomes excessive or when the holes 12 and M of whistle ill have been closed by the rising offloat l6, gas may escape through the auxiliary port 40, the pressure dislodging valve 42 from its seat. Excessive movement of the valve 42 is prevented by the guide member 44 and the housing 8.

The operation of float iii in the construction of Fig. 4 is the same as that in Fig. 3 in that the float rises under the influence of the rising liquid level first to distort the gas stream passing through the orifices and finally to close the orifices through the whistle. Whistling will cease when the gas stream is sufilciently distorted or the orifices closed, thereby giving the desired indication to the operator.

The construction shown in Fig. 5 is still another modification in which, during filling, the whistle is silent, but when the liquid level has risen to a predetermined point, whistling will commence, giving the indication to the operator.

In this construction whistle l0 rests on seat 34 of tank 2, and the ports l2 and H are normally closed by valve 48, which has depending therefrom a valve stem 48 extending through holes I! and I4, and on the lower end of which is a float l6. Guide means 50 may be provided so that float l8 and valve stem 68 may be constrained to move in a vertical direction. In the form shown, guide means 50 is connected with the underside of the whistle to. During the filling operation, as the gases cannot pass through the oriflces of the whistle, they are permitted to escape through the area created between the whistle i0 and seat 34 when the whistle is moved upwardly by the gas pressure. I

When, however, the liquid level rises to a point sufllcient to move float l6 upwardly, valv 46 will be moved away from the opening ii of the whistle, and when this movement has advanced sufliciently, the gases escaping through the orifices l2 and H of the whistle will produce a whistling sound to notify the operator that the tank is full. The whistling will be produced even though some of the gas, in the case where the pressure is excessive, may be escaping between the valveand seat 34.

The construction disclosed in Fig. 6 is much the same as that in Fig. 5 except that a short intrusion tube 52 has been added to depend into the tank a short distance below the tank top. This construction operates in the following manner. As filling proceeds, with the level below float l6, gas escapes from the tank by driving whistle l0 upwardly from its seat 34- to provide a passage, in accordance with the pressure,

through which the gas may reach vent pipe 6. When the liquid reaches and raises float 16, valve 46 will be raised from its position closing the whistle apertures, whereby gas may then escape through the whistle apertures i2 and H as well as around the seat 34. At this point, whistling commences, indicating to the operator that the level has at least reached the float. Thereafter, as filling continues, the whistle signal is maintained until such time as the liquid level reaches the lower end of intrusion tube 52. When this tube is trapped, gas may no longer escape through the whistle apertures, so that the signal will then cease. But gas may thereafter escape by passing between whistle I0 and seat 34, as it did prior to commencement of the whistling sound. The operator may then shut off the supply of liquid, leaving the tank practically full. The advantage of this construction is that it gives a preliminary warning when float i8 is raised and th whistle commences and a final warning when tube 52 is trapped and the whistle ceases.

In the forms shown in Figs. 3 and 4, float stops, as 22 in Fig. 2, may be provided to prevent complete closing of the whistle orifices, but at the same time permitting the float or float-operated means to approach the whistle sufficiently to cause cessation of whistling without cutting off the venting capacity.

In all of th constructions shown and described, it is apparent that the whistling is created or stopped by changing the character of the gas stream passing through the whistle rather than through any movement of the whistle itself. In some cases, the direction of the entering air stream is altered but not cut off. In other cases the gas passing through the whistle is cut off altogether. venting means is provided, as in Fig. 2, it will be noted that the orifices in the whistle are In the case where no auxiliary never sealed, so that a dangerous pressure condition within the tank cannot be created. In those cases where the orifices through the whistl are sealed, auxiliary venting means is provided which prevents the creation of dangerously excessive pressures.

In all cases it is apparent that we have provided means which extends downwardly into the tank a very short distance, and that the change in the audible signal is not .brought about until the tank is substantially full.

In the construction'shown, the float itself has acted directly to close, open or modify the venting orifices, but it should be understood that other mechanical equivalents operated by the float could be arranged to accomplish the same results.

While we have shown and described a number of modifications of our invention, we wish it to be understood that we do not intend to be limited thereby, 'but only by the appended claims.

We claim:

1. In combination, a tank having filling and venting means, a gas-operated sound-producing device positioned in the path of gases escaping from said tank, said device having orifices therethrough through which escaping gas may pass to produce an audible sound, float-operated means arranged to prevent fiow of gas through said orifices whenever the liquid level in the tank is below a predetermined point and to permit the flow of gas through said orifices only when the liquid level has risen at least to said predetermined point, and auxiliary venting means to permit the escape of gas from the tank during filling when the pressure in said tank exceeds a predetermined degree, said auxiliary venting means constituting the only means for the escape of g 'rom said tank during filling prior to the actuation of said float operated means caused by rising liquid.

2. In combination, a tank having filling and venting means, a gas-operated sound-producing device having a passageway therethrough, said device seated over an opening from said tank of greater area than said passageway, means obstructing said passageway to destroy the soundproducing quality of said device, a fioat connected to said obstructing means to cause removal of the latter from the proximity of said passageway when the liquid level has risen to a predetermined point whereby said device will produce an audible sound as gas flows therethrough in sufficient volume, said device capable of being unseated from said opening upon the development of sufilcient pressure in said tank to provide an auxiliary vent.

3. The combination set forth in claim 2 and including in addition a tube depending from said device into said tank and constituting a downward extension of said passageway, said tube terminating at a point above the normal position of said fioat whereby said audible signal may be terminated when the liquid level reaches said tube.

' FRANK P. SCULLY.

ALCIDE E. MATHEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Carr'nan Jan. 12, 1875 Morrison Apr. 30, 1895 Robertson Oct. 17, 1911 Colvin Mar. 3, 1931 Mathey Nov. 8, 1938 Crossley Jan. 10, 1939 Morse Jan. 10, 1939 Mathey Jan. 10, 1939 Biasco Mar. 28, 1939 Scully Aug. 27, 1940 Scully Dec. 31, 1940 Scully Dec. 31, 1940 Tapp Feb. 25, 1941 Scully Mar. 17, 1942 Scully Sept. 7, 1943 Number 

